Box spring assembly and improved springs therefor

ABSTRACT

A box spring assembly of the formed wire spring type comprising a plurality of spring members mounted on a supporting frame and connected together to form a spring deck disposed above the frame and yieldably movable toward the frame. Some or all of the springs are of an improved construction wherein each consists of a substantially horizontal body portion and depending end portions each of which comprises a plurality of angularly arranged connecting bars and substantially horizontal torsion bars. Alternate ones of the connecting bars are substantially closer to being horizontal in the unloaded condition of the springs than the remaining ones of the connecting bars, the remaining ones of the connecting bars extending upwardly from the alternate ones so that the remaining ones are more nearly vertical than the alternate ones. As a result, when the springs are subjected to downwardly directed loads, resistance to load is achieved by both twisting of the torsion bars and bending of some of the connecting bars.

United States Patent [191 Slominski et al.

[ Dec. 10, 1974 BOX SPRlNG ASSEMBLY AND IMPROVED SPRINGS THEREFOR [75] Inventors: Walter V. Slominski, Ann Arbor,

Mich.; Jack C. Mandusky, Lexington, Ky.

[73] Assignee: Hoover Bell and Bearing Company,

Saline, Mich.

[22] Filed: May 23, 1973 [21] Appl. No.: 362,887

Attorney, Agent, or Firin-Finri G. Olsen; James E. Stephenson Primary Examiner-Roy D. Frazier Assistant Examiner-Darrell Marquette [57] ABSTRACT A box spring assembly of the formed wire spring type comprising a'plurality of spring members mounted on a supporting frame and connected together to form a spring deck disposed above the frame and yieldably movable toward the frame. Some or all of the springs are of an improved construction wherein each consists of a substantially horizontal body portion and depending end portions each of which comprises a plurality of angularly arranged connecting bars and substantially horizontal torsion bars. Alternate ones of the connecting bars are substantially closer to being horizontal in the unloaded condition of the springs than the remaining ones of the connecting bars, the remaining ones of the connecting bars extending upwardly from the alternate ones so that the remaining ones are more nearly vertical than the alternate ones. As a result, when the springs are subjected to downwardly directed loads, resistance to load is achieved by both twisting of the torsion bars and bending of some of the connecting bars.

12 Claims, 9. Drawing Figures PATENIED H 1 3. 852 .838

sum 1 or 3 mcajl PAIENIED um a man sum 2 or 5 BOX SPRING ASSEMBLY AND IMPROVED SPRINGS THEREFOR BACKGROUND OF THE INVENTION For many years, box spring assemblies utilized conventional coil springs. My earlier US. No. 3,286,281 illustrates the first practical improvement on the conventional coil spring box assembly. The box spring assembly shown in that patent has been the basis for the most innovative advance in the box spring industry in many years, namely, the box spring assembly in which the springs are formed wire springs. This product has met with great commercial success and subsequent U.S. Nos. 3,487,480 and 3,574,241 show further improvements in the springs for the formed wire box spring assembly shown in my first US. Pat. No. 3,286,281. The object of the present invention is to provide a still further improved spring for the formed wire box spring assembly and a resulting improved assembly which will meet the new testing standards recently adopted by the industry.

SUMMARY OF THE INVENTION The box spring assembly of this invention consists of the usual supporting frame and a plurality of spring members mounted on the frame and connected together to form a spring deck disposed above the frame and yieldably movable toward the frame. Some or all of the springs which comprise the spring assembly are of the improved construction of this invention wherein each one has a substantially horizontal and straight body portion and depending end portions shaped to reduce the possibility of set in the spring and provide for increased user comfort.

Each of the spring end portions comprises a plurality of angularly arranged connecting bars and substantially horizontal torsion bars extending between and connecting adjacent connecting bars. Alternate ones of the connecting bars are substantially closer to being horizontal in the unloaded condition of the spring than the remaining ones of the connecting bars. These remaining connecting bars extend upwardly so that they are more nearly vertical than the alternate bars and are reversely inclined relative to the alternate bars. As a result, when the springs are subjected to downwardly directed loads, the alternate connecting bars are bent downwardly so that they cooperate with thetwisting torsion bars to yieldably resist load and'preclude any of the torsion bars from being twisted beyond their yield point. This spring geometry provides for smaller torsional angles in the spring thereby reducing angular twisting and reducing the likelihood of permanent set in the spring.

The box spring assembly includes wires which connect the end portions of each spring together so as to insure straight down movement of the end portions under load. This minimizes any tendency of the spring end portions to move laterally.

' In addition, the improved spring of this invention is provided in each end portion with a top connecting bar which is as long or longer than any of the other connecting bars in the end portion. This allows the top connecting bar to initially fold fairly easily when the spring is loaded. As the loading of the spring continues, the

'end portions stiffen. From the standpoint of the comfort of the sleeper this allows the mattress on the box spring assembly to conform initially to the shape of the sleeper and then provide an increasingly firm support for that shape.

Further objects, features and advantages of this invention will become apparent from a consideration of the following description, the appended claims, and the accompanying drawing in which:

FIG. 1 is a plan view of the improved box spring assembly of this invention;

FIG. 2 is a transverse sectional view of the box spring assembly of this invention as seen from substantially the line 22 in FIG. 1;

FIG. 3 is a fragmentary elevational view of one form of an end portion of the improved spring of this inven tion showing the spring in an unloaded condition;

FIGS. 4 and 5 are elevational views like FIG. 3 showing the spring in a progressively loaded condition;

FIG. 6 is a view like FIG. 3 of a modified form of the spring of this invention; and

FIGS. 7, 8 and 9 are elevational views of the modified form of the spring of this invention showing the spring in progressively loaded condition.

With reference to the drawing, the box spring assembly of this invention, indicated generally at 10, is illustrated in FIG. 1 as comprising a rectangular frame 12 with cross rails 13 and a spring assembly 14 mounted on and positioned above the frame 12. The spring assembly 14 consists of a plurality of main springs 16, arranged crisscross fashion above the frame 12, internal support springs 18 which are secured to and extended between the main springs 16, and a border wire 20. The springs 16 and 18 have horizontal and substantially straight body portions 22 and depending end portions 24 (FIG. 2) that are connected so that thebody portions 22 cooperate to form a horizontal spring deck 26 located a predetermined distance above the frame 12 in the unloaded condition of the springs 16 and 18. The principal improvement in the present invention is in the construction of the spring end portions 24. This construction is illustrated herein incorporated in all of the springs 16 and 18 but it is to be understood that the box spring assembly is also improved by incorporating this construction in only the internal support springs 18 or only the main springs 16.

As shown in FIG. 3, a spring end portion 24 includes alternate connecting bars 40 which are nearly horizontal and inclined only slightly upwardly and inwardly in the unloaded condition of the spring. The remaining connecting bars 42 are substantially parallel to each other and extend upwardly and outwardly and are more nearly vertical than the bars 40. The connecting bars are connected by conventional torsion bars 44 and a mounting foot 46 is secured to the frame 12, usually by staples. The uppermost connecting bar 42 which is connected to the body portion 22 is as long as or longer than the other torsion bars 42 and, as a result, the spring end portion 24 has an easy yieldable response to initial load. Further loading of the spring causes it to stiffen. When the spring end portion 24 is loaded so that they function with the torsion bars 44 to resist load and resist any tendency of any two adjacent connecting bars 40 and 42 to fold onto each other and cause a permanent set in the end portion 24.

As shown in FIG. 5, when the spring is further loaded to further deflect or compress the end portion 24, all of the connecting bars 40 and 42 have been rotated to more nearly vertical positions. This enables the spring to resiliently resist loads with less risk of permanent set. The fact that the spring ends are connected to the border wire 20 by clips 50 insures straight up and down movement of the end portions 24. This fixed distance relation of the ends of the body portion 22 limits lateral deflection of the end-portions 24 so that the movement depicted in FIGS. 3-5, inclusive, can be achieved. In the case of the internal springs 18, the main springs 16, by means of clips 51, connect the ends of the body portions 22 so that the spring end portions 24 will not deflect laterally during loading.

The springs 16 and 18 can be modified, within the purview of this invention, so as to have end portions 240 shaped as shown in FIGS. 6-9. Each end portion 24a has connecting bars 28 and 30 which extend downwardly from the body portion 22 and are in turn connected by horizontal torsion bars 32. A generally upright bar 34 is connected by torsion bars 32 to the lowermost connecting bar 28 and to a generally horizontal mounting foot 36. The foot 36 is securedin a suitable manner to the frame 12 so that the lowermost torsion bar 32 remains in a fixed position during loading of the spring deck 26.

In the unloaded condition of the spring end portion 24a, shown in FIGS. 6 and 7, the alternate connecting bars 28 are substantially parallel and are nearly horizontal. The remaining connecting bars 30 are inclined upwardly and outwardly and are much closer to being vertical than the bars 28. Also it should be noted that the uppermost outwardly and upwardly inclined connecting bar 30 is longer than the remaining connecting bars. As a result, when the spring is initially loaded to deflect the end portion 24a as shown in FIG. 8, the uppermost connecting bar 30 first moves downwardly fairly easily and then the spring stiffens up.

Also, it should be noted in FIG. 8 that the connecting bars 30 remain parallel and in a substantially upwardly and outwardly inclined direction. The connecting bars 28, on the other hand, are rotated through a substantially greater angle. In fact, as can be seen from a comparison of FIGS. 7 and 8, the connecting bars 28 were originally inclined slightly upwardly and inwardly (FIG. 7) and under load are inclined downwardly and inwardly (FIG. 8). Thus, the connecting bars 28 which were originally reversely inclined relative to the connecting bars 30 become, under load, inclined in the same direction. The upright spacer bar 34 functions to give height to the spring end portion 24a using a minimum of material. When the end portion 240 is fully loaded, as shown in FIG. 9, the connecting bars 30 remain in their upwardly and outwardly inclined configuration.

From the above description it is seen that this invention provides an improved box spring assembly in which the spring end portions 24 and 24a are particularly configured to obtain an improved spring action and improved spring life. In other words, the springs 24 and 24a provide increased comfort to a user of the box spring 10 over an increased period of time. This is due to the fact that the springs initially deflect easily so that the sleep support conforms to the shape of the user and then stiffens up to provide the desired firm support. In addition, since permanent set problems are avoided, the box spring assembly 10 has the capability of providing this increased comfort over a prolonged service life.

What is claimed is:

1. In a box spring assembly which includes a supporting frame, a plurality of spring members mounted on said frame and connected together to form a spring deck disposed above the frame and yieldably movable toward the frame, at least some of said springs comprising substantially horizontal body portions and depending end portions, each of said end portions comprising a plurality of angularly arranged connecting bars and substantially horizontal torsion bars extending between and connecting adjacent connecting bars, alternate ones of said connecting bars being substantially horizontal in the unloaded condition of said spring and other ones of said connecting bars extending obliquely upward from said alternate ones so that when said springs are subjected to downwardly directed loads said alternate connecting bars are bent downwardly and said other connecting bars are also bent downwardly so that they become inclined in the same direction as said alternate bars to thereby achieve resistance to load by both twisting of said torsion bars and bending of said connecting bars.

2. A box spring assembly according to claim 1 further including means connected to and extending between the end portions for one of said some springs maintaining said end portions in a fixed spaced relation and confining movement thereof to straight up and down directions.

3. A box spring assembly according to claim 2 wherein said means connected to and extending between said end portions comprises the body portions of other one of said spring members which form said deck. I 4. A box spring assembly according to claim 2 wherein said means connected to and extending between said end portions comprises a border wire encompassing said deck and located at the ends of the body portion for said one spring.

5. A box spring assembly according to claim 1 wherein said alternate ones of said connecting bars are reversely inclined relative to said other ones of said connecting bars in the unloaded condition of said spring and said alternate and said other ones of said connecting bars are inclined in the same direction in the loaded condition of said spring.

6. In a box spring assembly which includes a supporting frame, a plurality of spring members mounted on said frame and connected together to form a spring deck disposed above the frame and yieldably movable toward the frame, at least some of said springs comprising substantially horizontal body portions and depending end portions, each of said end portions comprising a plurality of angularly arranged connecting bars and substantially horizontal torsion bars extending between and connecting adjacent connecting bars, alternate ones of said connecting bars being substantially nearer to being horizontal in the unloaded condition of said spring than the remaining ones of said connecting bars, said remaining connecting bars extending obliquely upwardly from said alternate ones so that said remaining ones are reversely inclined relative to said alternate ones, said connecting bars being arranged relative to each other so that when said springs are subjected to downwardly directed loads said alternate connecting bars are bent downwardly so that they become inclined in the same direction as said remaining bars.

7. The structure according to claim 6 wherein each of said end portions includes a substantially horizontal mounting foot, there are two of such alternate ones of said connecting bars and three of said remaining connecting bars, the lower one of said remaining connecting bars being connected to and extending between said foot and the lower one of said alternate ones of said connecting bars.

8. The structure according to claim 7 wherein said lower connecting bar is substantially upright.

9. The structure according to claim 7 wherein said lower one of said connecting bars is substantially parallel to the remaining ones of said connecting bars.

10. A spring member comprising a one piece wire bent to form a substantially horizontal body portion having depending end portions, each of said end portions comprising a plurality of angularly arranged connecting bars and substantially horizontal torsion bars extending between and connecting adjacent connecting bars, alternate ones of said connecting bars, including the uppermost connecting bar that is adjacent said body portion, being oblique and inclined downwardly and inwardly, said alternate ones of said connecting bars being arranged in a substantially parallel relation, the remaining ones of said connecting bars being inclined to a substantially lesser degree than said first mentioned connecting bars, whereby on loading of said spring, said remaining connecting bars are moved through a substantially greater angle than said first mentioned bars toward positions inclined in the same general direction as said oblique bars.

11. The structure according to claim 10 wherein said remaining connecting bars are nearly horizontal in the unloaded condition of said spring.

v 12. The structure according to claim 11 further including means connected to and extending between said end portions confining movement of the ends of said body portion to straight up and down directions. 

1. In a box spring assembly which includes a supporting frame, a plurality of spring members mounted on said frame and connected together to form a spring deck disposed above the frame and yieldably movable toward the frame, at least some of said springs comprising substantially horizontal body portions and depending end portions, each of said end portions comprising a plurality of angularly arranged connecting bars and substantially horizontal torsion bars extending between and connecting adjacent connecting bars, alternate ones of said connecting bars being substantially horizontal in the unloaded condition of said spring and other ones of said connecting bars extending obliquely upward from said alternate ones so that when said springs are subjected to downwardly directed loads said alternate connecting bars are bent downwardly and said other connecting bars are also bent downwardly so that they become inclined in the same direction as said alternate bars to thereby achieve resistance to load by both twisting of said torsion bars and bending of said connecting bars.
 2. A box spring assembly according to claim 1 further including means connected to and extending between the end portions for one of said some springs maintaining said end portions in a fixed spaced relation and confining movement thereof to straight up and down directions.
 3. A box spring assembly according to claim 2 wherein said means connected to and extending between said end portions comprises the body portions of other one of said spring members which form said deck.
 4. A box spring assembly according to claim 2 wherein said means connected to and extending between said end portions comprises a border wire encompassing said deck and located at the ends of the body portion for said one spring.
 5. A box spring assembly according to claim 1 wherein said alternate ones of said connecting bars are reversely inclined relative to said other ones of said connecting bars in the unloaded condition of said spring and said alternate and said other ones of said connecting bars are inclined in the same direction in the loaded condition of said spring.
 6. In a box spring assembly which includes a supporting frame, a plurality of spring members mounted on said frame and connected together to form a spring deck disposed above the frame and yieldably movable toward the frame, at least some of said springs comprising substantially horizontal body portions and depending end portions, each of said end portions comprising a plurality of angularly arranged connecting bars and substantially horizontal torsion bars extending between and connecting adjacent connecting bars, alternate ones of said connecting bars being substantially nearer to being horizontal in the unloaded condition of said spring than the remaining ones of said connecting bars, said remaining connecting bars extending obliquely upwardly from said alternate ones so that said remaining ones are reversely inclined relative to said alternate ones, said connecting bars being arranged relative to each other so that when said springs are subjected to downwardly directed loads said alternate connecting bars are bent downwardly so that they become inclined in the same direction as said remaining bars.
 7. The structure according to claim 6 wherein each of said end portions includes a substantially horizontal mounting foot, there are two of such alternate ones of said connecting bars and three of said remaining connecting bars, the lower one of said remaining connecting bars being connected to and extending between said foot and the lower one of said alternate ones of said connecting bars.
 8. The structure according to claim 7 wherein said lower connecting bar is substantially upright.
 9. The structure according to claim 7 wherein said lower one of said connecting bars is substantially parallel to the remaining ones of said connecting bars.
 10. A spring member comprising a one piece wire bent to form a substantially horizontal body portion having depending end portions, each of said end portions comprising a plurality of angularly arranged connecting bars and substantially horizontal torsion bars extending between and connecting adjacent connecting bars, alternate ones of said connecting bars, including the uppermost connecting bar that is adjacent said body portion, being oblique and inclined downwardly and inwardly, said alternate ones of said connecting bars being arranged in a substantially parallel relation, the remaining ones of said connecting bars being inclined to a substantially lesser degree than said first mentioned connecting bars, whereby on loading of said spring, said remaining connecting bars are moved through a substantially greater angle than said first mentioned bars toward positions inclined in the same general direction as said oblique bars.
 11. The structure according to claim 10 wherein said remaining connecting bars are nearly horizontal in the unloaded condition of said spring.
 12. The structure according to claim 11 further including means connected to and extending between said end portions confining movement of the ends of said body portion to straight up and down directions. 